Manipulation of light signaling and nitric oxide metabolism as a means of improving tomato quality traits

Abstract

Fleshy fruit growth and ripening are under strict developmental, hormonal and epigenetic regulation, which in turn are fine-tuned by a plethora of environmental stimuli. Among environmental cues, light plays a significant role in determining fruit growth, pigmentation and timing of ripening. In tomato (Solanum lycopersicum), a major model species for fleshy fruits and leading vegetable crop, several lines of evidence indicate that changes in phytochrome(PHY)-dependent light perception and signaling can lead to significant alterations in fruit development and quality traits. Similarly, recent studies implicate the free radical nitric oxide (NO) as a key regulatory signal controlling fruit metabolism and ripening. Therefore, by applying functional genomic, biochemical and physiological approaches, this project aims to investigate the impacts of manipulating light perception and signal transduction as well as NO metabolism on tomato fruit biology. The specific role played by fruit-localized phytochromes and their downstream signaling cascades on regulating biochemical and developmental processes that directly impact major features of tomato fruit nutritional quality will be investigate both in an isolated or combined manner. Moreover, genes, proteins and metabolic processes controlled by NO during tomato ripening will be identified under both optional and stressful environmental conditions via both genetic and pharmacological approaches. (AU)